From: Larry Roohr (lrryr@home.com)
Date: 07/05/01-08:54:26 AM Z
Hi Katherine,
Is there a gum printing paper you would recomend for maximizing detail from
neg to print?
I may give paper negatives a shot as the sharpest paper is also the least
expensive and available in large sizes, Epson archival matte. The pictorico
is pricey and spraying it with yucky stuff probably trades off even with
oiling as far as time/trouble goes. What do you use for oiling your paper?
Thanks,
Larry
----- Original Message -----
From: "Katharine Thayer" <kthayer@pacifier.com>
To: <alt-photo-process-l@skyway.usask.ca>
Sent: Wednesday, July 04, 2001 3:20 PM
Subject: Re: digital gum negatives
> Smieglitz@aol.com wrote:
> >
> > In a message dated 07/04/2001 21:12:57, holtsg@duke.usask.ca wrote:
> >
> If you wish, Photoshop can be
> > used to color separate a CMYK image file and print the 4 negatives
> > automatically. But, this changes the original RGB file info a bit, so I
> > usually just print the 3 channels from the RGB file.
>
> Hi Joe and all,
>
> I agree that RGB separations are preferable to CMYK separations but if I
> understand what Gordon's trying to do, he's not working from a colored
> image but a BW pinhole image, which he wants to selectively color,
> possibly using masks? At any rate color separations shouldn't be an
> issue here.
>
> I've always avoided the problem of ink pooling on inkjet transparencies
> by using paper negatives when using the inkjet printer for digital
> negatives. There's *perhaps* a slight tradeoff in softness but none in
> speed; my oiled paper negatives print faster than film negatives.
>
> I've never seen dots on either my Epson photo-series negatives or prints
> made from them, even one-coat prints (although I have on negatives and
> prints made from Epson printers that weren't photo series printers, like
> the 3000). What's interesting is that sometimes there would be a very
> fine banding on the negative that I wouldn't see even though I inspected
> the negatives by eye before using them. But then when I made the print,
> there would be the fine lines in the gum print, and I'd go back and look
> at the negative with a loupe, and there they were. It's very annoying to
> have to throw out both the negative AND the print but that banding is
> one of the few things that can't be corrected. So I'd suggest that
> Gordon watch for those. It either means your print heads need cleaning
> or the printer doesn't like the media type you've specified.
> kt
>
>
>
> >
> > By all means give the 700 a try. Although the dots will be slightly
> > apparent, the gum printing process tends to eliminate them in the print.
> > Slight misregistration and dimensional instability of the paper with
multiple
> > printings and wet/dry cycles tends to fill in the spaces between the
dots.
> > The result is very acceptable with the multiple gum process (although I
find
> > the dot pattern distracting in single coat cyanotypes or VDBs.)
> >
> > You might find lower contrast files will print better. (There seems to
be a
> > huge jump in %ink output on one end of the scale with the Epson
printers.)
> > The contrast can be adjusted in Photoshop's curves or levels dialog box
> > without clipping the file data. (OTOH, the brightness/contrast control
> > eliminates data, so I wouldn't use it.) I also suspect the adjustment
curve
> > I posted a few days ago will produce better output of the channels on
the 700
> > or similar printers, although I haven't tested it on models other than
the
> > 1160 with the quadtone inks. With that system the curve essentially
> > eliminates the jump in %ink towards the upper end of the scale and
produces a
> > low contrast negative that prints about 6 steps of a Stauffer wedge at
max D
> > with minimum time with a single gum coat.
> >
> > Let me know if you have any questions as you give it a try. I'd also
like to
> > see the results.
> >
> > Joe
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